Climate-Altering Sheep and Things

Most of us have at least heard something about cattle and their substantial contribution to our modern day carbon footprint.
But it turns out that they are only the worst animal offender because of their quantity. Pound for pound sheep are actually worse, since they produce higher quantities of methane (by weight) but have less edible meat. (Kilograms of CO2-equivalent per kilo of food consumed are 27 for cows and 39.2 for sheep.)
And do you want to know what the number 3 "climate-altering" food is? Cheese! Yep, that's right. Cheese has a larger carbon footprint than pigs, or chickens. This is partly due to the production process involved and because it takes about 10 gallons of milk to make one pound of cheese.
The report by the Environmental Working Group Meat Eater's Guide to Climate Change and Health reports that if we all skipped eating cheese once a week it would be equivalent to taking 7.6 million cars off the road. Now on the face of it that doesn't seem like it could be true, and I am not sure how they figured that out, but even if it was only 1.6 million, that would still be pretty amazing!
I kind of feel "sheepish" now about having eaten my grilled mac and cheese sandwich yesterday.